Good morning. I'm Mary Louise Kelly, and I have a safe bet for you this weekend - put your money on an American woman. All four players to reach the semis at the U.S. Open are American. The last time that happened was 1981, when the lineup was Martina Navratilova, Chris Evert, Barbara Potter and Tracy Austin. Serena Williams will not be there delivering her trademark power serve. She delivered something else last week - a baby girl. It's MORNING EDITION. Transcript provided by NPR, Copyright NPR.